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DTC P0402 w/Block & Finger

btfarm

America First!
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I threw P0402 - EGR Excess Flow - 4 times during my 2500+ mile trip last week. I cleared them each time at fuel or pit stops and the truck ran fine anyhow. Thing is, I am blocked and fingered and on a Predator 85 tune. I've never had that EGR code during the 20k+ miles it's been in there and the Predator tune has been in for 35k+. I'm wondering what changed. I WAS running straight #2 w/o BIO for the first time in a couple of years. Averaged 66 mph and 17.3 mpg. I also noticed some HEAVY soot at the infrequent times I leaned into it but that's cleared up some since I've 'cleaned' it a bit more often.
Comments?
 
Anyone? I've thrown that code a couple more times since my return and rather that clear it I decided to see how many key cycles to clear the MIL. 1st time 4 cycles. I've got 2 key cycles on another one.
I'm thinking a worn out EGR motor or a ton of crap in the intake.?
 
I'll have to screw around and see if they are ok but I'd bet they are. I know the solution is to go EFI and turn all the egr codes off but there is zero budget for that direction now.
 
I had a similar setup to yours and I coded out at about 35k. Turned out to be the EGR motor being gummed up. I took the plate and stick out and drove it hard a few times and it cleared. I have switch to EFI since then, and haven't had any issues since then.
 
Mike, have you checked to see if you have any blow-by due to the gasses leaking by the blocker? Just a thought. Maybe tighten the blocker plate? I too thought the stick was supposed to block out all codes. Maybe a call to Fingers? Or Kennedy?
 
Mike did you solder the connections? If not checking the stick connections is worth a shot. If they are all good I would suspect the EGR as the stick takes care of the flow codes P0401 and P0404. Any exhaust leak will stay in the engine bay as the flow is from back to front.
 
Yep, they were soldered. I did check the external (yellow wire) one yesterday and it seemed good. Haven't had time to open up the box and check the rest. I checked for leaks at the blocker before and it's good. Never thought I'd have to pull this stuff out and blow it out. It codes so infrequently it's hardly an issue and 3 key cycles delete it if I don't get to it with the scan tool.
 
Mike, I read this code is set when there is an air leak between the MAF and the turbo. Check the resonator also not just the worm clamp but the crimp clamp too. While you are in there I would give each clamp a twist to make sure they are all tight.
 
Put the cap back on in place of the resonator a couple of days ago and checked (snugged) the hose clamps. My 402 friend came back this eve. Further checking is in order... Irritating issue but certainly not earth shattering...
BTW, I also checked the nuts at the plate and they are tight.
I still think this may be a sign of a bad EGR or EGR motor. Can you run with the EGR motor connector off? I know a code will be up but their might be something else related to the motor being defective.
 
Put the cap back on in place of the resonator a couple of days ago and checked (snugged) the hose clamps. My 402 friend came back this eve. Further checking is in order... Irritating issue but certainly not earth shattering...
BTW, I also checked the nuts at the plate and they are tight.
I still think this may be a sign of a bad EGR or EGR motor. Can you run with the EGR motor connector off? I know a code will be up but their might be something else related to the motor being defective.

It will code, but probably nothing that will not allow you to drive it? But, I'm afraid of it "hung" in once place and the engine not operating as efficently as it can.

Also Mike, I know I said something about this is another thread. But, since your warranty is gone, before spending WAY to much money on a new/used EGR grab a delete kit!

I know my next truck (play truck, b/c I'm not touching this one), that will be the first thing I do after seeing the gains from it.
 
Jeff, who's kit do you suggest?

Good question Bill. I've heard nothing but good from both the Allseason, RDL, and even the Alligator Kit (rebadged?). I would have to research closer when the time comes.
 
I looked at Tony's (Allseasons) delete kit when I did the block and PCV deal. I'm trying to avoid the cost right now but if I had to replace the EGR you can bet it will be out of the picture for good.
 
For the sake of information related to this...
When the MIL turns off after 5 key cycles, the next time it throws the same P0402 it will not have the prior code still in there. Being a soft malfunction means it's not stored I guess.
Another thing, the MIL comes on "out of the blue" for this code when just driving along minding your own business at a steady speed. Not at WOT or closed throttle under TH grade brake or any stressful situation to make you think you did something bad. It's more of a :WTF: where'd that come from :???: kinda thing.
 
Update

I was getting a good 4-5 P0402s a week and it got irritating. About 5 weeks ago I pulled the harness cover off and checked all the finger connections. All were good so I re-taped and I decided to leave it out in the open rather than in the box this time.

Now it's like this:
FingerReloc.jpg

1st thing I noticed is I next threw a code a week later, twice in a row.

Now it's been about 3+ weeks with no MIL. I was thinking about how long it had been this morning and... you guessed it... It threw one.
I think having pressure on the circuit when it is stuffed in the box combined with extra heat has something to do with it.
Anyhow, it's much more livable these days.
 
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